Abstract: A method for automatically initiating the flow of fluid in a pipe that may be blocked by frozen fluid in a portion of the pipe includes urging the flow of fluid through the pipe and energizing a heater disposed in and extending the pipe portion if no flow is detected in the pipe.

Abstract: A solar hot water system includes a mirror which reflects solar energy on an absorber including a water pipe and two plates to heat water in the pipe. When water in the pipe freezes and expands, the pipe and the plates are elastically deformed without injury.

Abstract: A walking cane includes a length of flexible material forming at least a portion of a closed loop, the loop freestanding above the grip portion of the cane handle when unstressed. The loop has a perimeter defining an opening capable of receiving the hand of a user inserted through the loop to grasp the grip portion of the handle. The end portions of the loop extend below the cane handle and enable the handle to be securely positioned on a surface when the cane is temporarily not in use.

Abstract: A hot water solar heating system includes a solar collector assembly located outside a building, a hot water tank located inside the building and supply and return pipes connecting the tank to the solar collector assembly. Portions of the supply and return pipes are located outside the building and are subject to below freezing temperatures and ice blockages. The system includes resistance heating wires which melt ice blockages in the exterior portions of the supply and return pipes.

Abstract: A bone cement mixer having a cartridge filled with bone cement powder and a monomer well for receiving monomer liquid to be flowed into the bone cement powder. The monomer liquid flows by gravity in a stream near the outer periphery of the bone cement powder. The stream penetrates the bone cement powder and forms a partial cylinder of monomer-rich powder essentially uniformly along the height of the bone cement powder. The powder and liquid are then mechanically mixed to form bone cement.

Abstract: An improved ampule breaker that is snapped over an ampule tip and held in a desired location with a collar flush against the top of an ampule body, a stiff ring fulcrum support surrounding the score line in the neck of an ampule and the ampule tip closely surrounded by a plurality of locating ribs. The ampule tip is broken away from the ampule body by rotating the breaker to one side of the ampule so that the tip is rotated about the ring fulcrum and is broken away from the ampule body at the score line with a smooth break and without the formation of shards.

Abstract: A device for stirring bone cement includes a bone cement cartridge having a piston at one end of the cartridge and an elongate stirrer extending through the piston and along the cartridge. Bone cement powder and liquid are mixed in the cartridge by relative rotation between the cartridge and stirrer. The mixed bone cement is extruded from the cartridge by moving the piston along the cartridge and the stirrer.

Abstract: A bone cement mixer having a cartridge housing for receiving an open bone cement cartridge filled with bone cement powder with a stirrer in the cartridge, and a cover which is fitted over the housing to define a vacuum chamber. The chamber is evacuated and monomer liquid is flowed into the bone cement powder in the cartridge in a stream that penetrates the bone cement powder and distributes monomer liquid essentially uniformly along the height of the bone cement powder. The powder and liquid are then mechanically mixed to form bone cement.

Abstract: A bone plate includes a pair of mounting portions with bridges extending between the mounting portions. Each bridge includes at least one spring member and a compression member, arranged in series.

Abstract: A system for mixing bone cement is disclosed. Dry PMMA powder and MMA liquid are mixed in a vacuum chamber. Gas from the mixture is vacuum drawn from the mixer by a vacuum source through a vacuum tube which extends between the mixer and the vacuum source. The vacuum source is actuated by creating a positive pressure pulse in the vacuum tube. The pressure pulse may be caused by closing the lid of the mixer, by squeezing an in-line pressure bulb in the vacuum tube or by squeezing a pressure bulb joined to the vacuum tube. The vacuum source is automatically deactivated when a positive vacuum pulse is detected. The second pressure pulse is caused when the vacuum tube is disconnected from the vacuum chamber.

Abstract: A device for mixing bone cement of the present invention includes a housing having an open top. An internal chamber is located in the housing. The internal chamber is inclined at an angle from a vertical axis. The device further includes a mixer having stirrer elements extending into the internal chamber and a cap configured to fit over the open top of the housing to sealably close the housing. The method of mixing bone cement according to the present invention includes the steps of placing bone cement powder into an inclined chamber, introducing bone cement liquid into the inclined chamber and then mixing the bone cement liquid and bone powder to form mixed bone cement.

Abstract: An apparatus for retaining a bone site in a fixed position and guiding a high speed power tool for machining the bone, such as a patella, including a positioner frame for rigid attachment about the bone site. The frame includes a bone clamping mechanism capable of adjustment and orientation of the bone site relative to the frame. A hinged power tool mount attaches to the frame and is adapted to receive a power tool for machining the bone in a predetermined manner. A power tool is received by the mount. A template corresponding to the predetermined manner attaches to the positioner frame for guiding the power tool. The bone clamping mechanism includes a plurality of gripping assemblies adapted to grip the bone about multiple locations. A depth adjustment guide is provided in the frame, which is adapted to cooperate with the power tool for controlling the depth the cut. A method for using the apparatus is also disclosed.

Abstract: A bone or dental cement mixing method and preform body are disclosed. An elongate rod is inserted into a cement mixing chamber. Cement powder is poured into the mixing chamber and around the rod to form a preform body in the chamber. The rod is moved laterally through the powder to form a channel in the body. Cement liquid is poured on top of the body, flows down the channel and is absorbed into the body. The body and liquid are then physically mixed by a conventional cement mixing device to form a cement with cement liquid uniformly distributed throughout the cement.

Abstract: A system for mixing bone cement is disclosed. Dry PMMA powder and MMA liquid are mixed in a vacuum chamber by a rotary mixer having a pair of spaced mixing arms. The rotary mixer is manually rotated by a gear drive. The arms of the rotary mixer follow continuous paths, each path having a plurality of loops at the wall of the chamber and curved portions extending across the chamber between loops. The arms move through the cement, break bubbles and thoroughly mix the PMMA and MMA. Gas from broken bubbles is vacuum drawn from the mixer by a vacuum source through a vacuum tube which extends between the mixer and a vacuum source. The vacuum source is automatically deactivated when the vacuum tube is detached from the mixer.

Abstract: A device for mixing bone cement is disclosed. Dry PMMA powder and MMA liquid are mixed in a vacuum chamber by a rotary mixer having a pair of spaced mixing arms. The rotary mixer is manually rotated by a gear drive. The arms of the rotary mixer follow continuous paths, each path having a plurality of loops at the wall of the chamber and curved portions extending across the chamber between loops. The arms move through the cement, break bubbles and thoroughly mix the PMMA and MMA. Gas from broken bubbles is vacuum drawn from the mixer to a vacuum source.

Abstract: A method for mixing bone cement by mixing PMMA powder and MMA liquid in a vacuum chamber using a rotary mixer having a pair of spaced mixing arms. The rotary mixer is manually rotated by a gear drive. The arms of the rotary mixer follow continuous paths, each path having a plurality of loops at the wall of the chamber and curved portions extending across the chamber between loops. The arms move through the cement, break bubbles and thoroughly mix the PMMA and MMA. Gas from broken bubbles is vacuum drawn from the mixer by a vacuum source. The vacuum source is deactivated when a vacuum tube is detached from the mixer.

Abstract: A method of making a rigid body from an acrylic cement powder by first compacting the powder so that adjacent particles are cohesively bonded together and a network of passages extend between the particles and then flowing a solvent vapor through the interior passages to form solvent bonds between particles.

Abstract: An apparatus and technique for fluid level determination in automatic transmissions. The invention employs an electronic control unit in association with an automatic transmission for a vehicle, the electronic control unit receiving data corresponding to transmission oil level, transmission oil temperature, engine speed, transmission speed, and transmission selected range. Upon determining that such data satisfies certain diagnostic tests, the level of transmission fluid within the transmission is determined and adjusted or otherwise normalized to ideal test conditions. The electronic control unit compensates an oil level signal for deviations in oil temperature from an optimum test temperature, and makes further compensation for deviations in engine speed and settling time at the time that the test data is acquired. Additionally, variations in oil density as a function of oil temperature are also compensated.

Abstract: Dental and orthopedic acrylic cements are mixed by forming cement powder into a body in which adjacent particles are bonded to each other while defining a continuous open network of passages extended throughout the body and then brining the body in contact with cement liquid. The liquid is wicked throughout the passages to dissolve the bonds and form a mixed cement without stirring.

Abstract: Dental and orthopedic acrylic cements are mixed by forming cement powder into a body in which adjacent particles are bonded to each other while defining a continuous open network of passages extending throughout the body and then bringing the body in contact with cement liquid. The liquid is wicked throughout the passages to dissolve the bonds and forms a mixed cement without stirring.